1. Technical Field
This disclosure relates generally to a turbine engine and, more particularly, to a variable area vane arrangement for a turbine engine.
2. Background Information
A typical turbine engine includes a fan section, a compressor section, a combustor section and a turbine section. The turbine engine may also include a plurality of variable area vane arrangements. Each variable area vane arrangement may guide and/or adjust a flow of core gas in one or more turbine stages. Alternatively, the variable area vane arrangement may guide and/or adjust the flow of core gas between an upstream engine section and an adjacent downstream engine section.
A typical variable area vane arrangement includes a plurality of adjustable stator vanes that extend between a radial outer vane platform and a radial inner vane platform. An outer radial end of each stator vane is rotatably connected to the outer vane platform with an outer shaft and a bearing. An inner radial end of each stator vane is rotatably connected to the inner vane platform with an inner shaft and a bearing. The outer shaft may include a bore that directs cooling air from a plenum, adjacent the outer vane platform, into a cavity within an airfoil of the respective stator vane. Airfoil cooling apertures may subsequently direct the cooling air out of the cavity to film cool the outer surfaces of the airfoil that are exposed to the core gas. To provide a sufficient quantity of the cooling air, the outer shaft bore typically has a relatively large diameter. As the diameter of the outer shaft bore increases, however, the size of the bearing also increases, which may increase the weight, cost and complexity of the vane arrangement.
There is a need in the art for an improved variable area vane arrangement.